It was a filmmaking experience that changed her life as well as the lives of survivors, Angelina Jolie told Telluride Film Festival attendees who screened her new Netflix film, First They Killed My Father: A Daughter of Cambodia Remembers, which received a standing ovation. The audience affection seemed split between her movie and another labor of love, her children. Jolie attended the event with her entire brood of six: Maddox, 16; Pax, 13; Zahara, 12; Shiloh, 11 and twins Vivienne and Knox, 9.

The project, which Jolie directed and co-wrote, documents author Loung Ung’s experience as a child soldier under the horrific Khmer Rouge regime that seized control of Cambodia in 1975, brutalizing the people in a reign of terror and genocide.

The historical episode has special meaning for the Jolie family, since her son Maddox was adopted from a Cambodian orphanage in 2002. Jolie spoke movingly about her experience screening the film for Cambodian survivors, an effort that involved the cooperation of the king as well as the government.

“We ended up at Terrace of the Elephant in Angkor Wat,” Jolie said, “which is very special to the Cambodian people, screening outside, and it was extraordinary. It was so moving to see everybody watch. A lot of them said that night they were able to talk about it for the first time.” Jolie underscored the global power of film to move hearts and minds.

Relaxing onstage in a director’s chair alongside Ung after the screening, Jolie admitted that during a visit several years ago she was struck by how “ignorant” she was about what had happened in Cambodia. “I met people who had returned from the border camps, and was warned about land mines,” she recalled. “But most of all I met people whose spirits were high. They’re so generous. They’re so gracious. Their culture is so strong and I was so impressed by them. And during that trip I picked up a $2 book on a street corner, and it was [Ung’s] book. It changed my life.”

First They Killed My Father is scheduled for a Sept. 15 premiere on Netflix.